The contiguity of land may be inferred not only from these vegetable productions, but also from the teeth and bones of crocodiles and turtles, since these creatures, as Mr. Conybeare has remarked, must have resorted to some shore to lay their eggs. Of turtles there were numerous species referred to extinct genera, and, for the most part, not equal in size to the largest living tropical turtles. A snake, which must have been 13 feet long, of the genus _Palaeophis_ before mentioned, has also been described by Mr. Owen from Sheppey, of a different species from that of Bracklesham. A true crocodile, also, _Crocodilus toliapicus_, and another Saurian more nearly allied to the gravial, accompany the above fossils. A bird allied to the vultures, and a quadruped of the new genus _Hyracotherium_, allied to the Hyrax, Hog, and Chaeropotamus, are also among the additions made of late years to the palaeontology of this division. [3 Illustrations: FOSSIL SHELLS OF THE LONDON CLAY. Fig. 176. _Mitra scabra_. Fig. 177. _Rostellaria macroptera_, Sow. One-third of nat. size. Fig. 178. _Crassatella sulcata._] The marine shells of the London clay confirm the inference derivable from the plants and reptiles of a high temperature. Thus, many species of _Conus_, _Mitra_, and _Voluta_ occur, a large _Cypraea_, a very large _Rostellaria_, and shells of the genera _Terebellum_, _Cancellaria_, _Crassatella_, and others, with four or more species of _Nautilus_ (see fig. 182.) and other cephalopoda of extinct genera, one of the most remarkable of which is the _Belosepia_.[202-A] (See fig. 183.) [Illustration: Fig. 179. _Nautilus centralis._] [Illustration: Fig. 180. _Voluta athleta._] [Illustration: Fig. 181. _Terebellum fusiforme._] [Illustration: Fig. 182. _Aturia zigzag._ Bronn. Syn. _Nautilus zigzag._ Sow. London clay. Sheppey.] [Illustration: Fig. 183. _Belosepia sepiodea_, De Blainv. London clay. Sheppey.] The above shells are accompanied by a sword-fish (_Tetrapterus priscus_, Agassiz), about 8 feet long, and a saw-fish (_Pristis bisulcatus_, Ag.), about 10 feet in length; genera now foreign to the British seas. On the whole, no less than 50 species of fish have been described by M. Agassiz from these beds in Sheppey, and they indicate, in his opinion, a warm climate. [Illustration: Fig. 184. Molar of monkey (_Macacus_).]